// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: http://codemirror.net/LICENSE

(function (mod) {
    if (typeof exports == "object" && typeof module == "object") // CommonJS
        mod(require("../../lib/codemirror"));
    else if (typeof define == "function" && define.amd) // AMD
        define(["../../lib/codemirror"], mod);
    else // Plain browser env
        mod(CodeMirror);
})(function (CodeMirror) {
    var ie_lt8 = /MSIE \d/.test(navigator.userAgent) &&
        (document.documentMode == null || document.documentMode < 8);

    var Pos = CodeMirror.Pos;

    var matching = {"(": ")>", ")": "(<", "[": "]>", "]": "[<", "{": "}>", "}": "{<"};

    function findMatchingBracket(cm, where, strict, config) {
        var line = cm.getLineHandle(where.line), pos = where.ch - 1;
        var match = (pos >= 0 && matching[line.text.charAt(pos)]) || matching[line.text.charAt(++pos)];
        if (!match) return null;
        var dir = match.charAt(1) == ">" ? 1 : -1;
        if (strict && (dir > 0) != (pos == where.ch)) return null;
        var style = cm.getTokenTypeAt(Pos(where.line, pos + 1));

        var found = scanForBracket(cm, Pos(where.line, pos + (dir > 0 ? 1 : 0)), dir, style || null, config);
        if (found == null) return null;
        return {
            from: Pos(where.line, pos), to: found && found.pos,
            match: found && found.ch == match.charAt(0), forward: dir > 0
        };
    }

    // bracketRegex is used to specify which type of bracket to scan
    // should be a regexp, e.g. /[[\]]/
    //
    // Note: If "where" is on an open bracket, then this bracket is ignored.
    //
    // Returns false when no bracket was found, null when it reached
    // maxScanLines and gave up
    function scanForBracket(cm, where, dir, style, config) {
        var maxScanLen = (config && config.maxScanLineLength) || 10000;
        var maxScanLines = (config && config.maxScanLines) || 1000;

        var stack = [];
        var re = config && config.bracketRegex ? config.bracketRegex : /[(){}[\]]/;
        var lineEnd = dir > 0 ? Math.min(where.line + maxScanLines, cm.lastLine() + 1)
            : Math.max(cm.firstLine() - 1, where.line - maxScanLines);
        for (var lineNo = where.line; lineNo != lineEnd; lineNo += dir) {
            var line = cm.getLine(lineNo);
            if (!line) continue;
            var pos = dir > 0 ? 0 : line.length - 1, end = dir > 0 ? line.length : -1;
            if (line.length > maxScanLen) continue;
            if (lineNo == where.line) pos = where.ch - (dir < 0 ? 1 : 0);
            for (; pos != end; pos += dir) {
                var ch = line.charAt(pos);
                if (re.test(ch) && (style === undefined || cm.getTokenTypeAt(Pos(lineNo, pos + 1)) == style)) {
                    var match = matching[ch];
                    if ((match.charAt(1) == ">") == (dir > 0)) stack.push(ch);
                    else if (!stack.length) return {pos: Pos(lineNo, pos), ch: ch};
                    else stack.pop();
                }
            }
        }
        return lineNo - dir == (dir > 0 ? cm.lastLine() : cm.firstLine()) ? false : null;
    }

    function matchBrackets(cm, autoclear, config) {
        // Disable brace matching in long lines, since it'll cause hugely slow updates
        var maxHighlightLen = cm.state.matchBrackets.maxHighlightLineLength || 1000;
        var marks = [], ranges = cm.listSelections();
        for (var i = 0; i < ranges.length; i++) {
            var match = ranges[i].empty() && findMatchingBracket(cm, ranges[i].head, false, config);
            if (match && cm.getLine(match.from.line).length <= maxHighlightLen) {
                var style = match.match ? "CodeMirror-matchingbracket" : "CodeMirror-nonmatchingbracket";
                marks.push(cm.markText(match.from, Pos(match.from.line, match.from.ch + 1), {className: style}));
                if (match.to && cm.getLine(match.to.line).length <= maxHighlightLen)
                    marks.push(cm.markText(match.to, Pos(match.to.line, match.to.ch + 1), {className: style}));
            }
        }

        if (marks.length) {
            // Kludge to work around the IE bug from issue #1193, where text
            // input stops going to the textare whever this fires.
            if (ie_lt8 && cm.state.focused) cm.focus();

            var clear = function () {
                cm.operation(function () {
                    for (var i = 0; i < marks.length; i++) marks[i].clear();
                });
            };
            if (autoclear) setTimeout(clear, 800);
            else return clear;
        }
    }

    var currentlyHighlighted = null;

    function doMatchBrackets(cm) {
        cm.operation(function () {
            if (currentlyHighlighted) {
                currentlyHighlighted();
                currentlyHighlighted = null;
            }
            currentlyHighlighted = matchBrackets(cm, false, cm.state.matchBrackets);
        });
    }

    CodeMirror.defineOption("matchBrackets", false, function (cm, val, old) {
        if (old && old != CodeMirror.Init)
            cm.off("cursorActivity", doMatchBrackets);
        if (val) {
            cm.state.matchBrackets = typeof val == "object" ? val : {};
            cm.on("cursorActivity", doMatchBrackets);
        }
    });

    CodeMirror.defineExtension("matchBrackets", function () {
        matchBrackets(this, true);
    });
    CodeMirror.defineExtension("findMatchingBracket", function (pos, strict, config) {
        return findMatchingBracket(this, pos, strict, config);
    });
    CodeMirror.defineExtension("scanForBracket", function (pos, dir, style, config) {
        return scanForBracket(this, pos, dir, style, config);
    });
});
